Sterilizing device



Oct. 11, 1949. o. H. BREWSTER STERILIZING DEVICE Filed Jan. 5, 1946 m m m m OLIVER 'H. BREWSTER,

7 AITTO Y.

Patented Oct. 11, 1949 s'rniuuzme DEVICE Oliver H. Brewster, Essex Fells, N. J assignor to Electrical Industries, Inc., Newark, N. J a corporation of New Jersey Application January 5, 1946, Serial No. 639,259

8 Claims. (01.2149) The present invention relates to devices for sterilizing open-mouth receptacles and, particularly, to sterilizing devices of the fluid-conduction type which concentrate heated vapor on a predetermined portion of an open-mouth receptacle being sterilized. As employed in this specification, the term fluid-conduction type sterilizing device is intended to designate a sterilizer which employs a liquid that is vaporized by the passage of electrical current through the liquid.

In prior fluid-conduction types of sterilizing devices, the vapor generated by the passageof electrical current through the liquid contained therein ascends through a plurality of apertures in a perforated support for the article being sterilized and completely encompasses the article.

In many applications an arrangement of this character is entirely satisfactory. For some purposes, however, it is desirable that the hot vapor be concentrated principally in a predetermined region. For example, in the sterilization of receptacles such as infants nursing bottles, a quicker and more effective sterilization is achieved when a major portion of the sterilizing vapor is directed into the interior of the bottles to destroy bacteria and other microorganisms, thus avoiding the contamination of the nursing fluid later to be placed therein- It is an object of the present invention, therefore, to provide a new and improved sterilizing device of the fluid-conduction type which is adapted to sterilize open-mouth receptacles.

It is a furthe'r object of the invention to provide a new and improved sterilizing device of the fluid-conduction type which is simple in construction, relatively inexpensive to manufacture, and both easy and economical to operate.

.In accordance with the invention, a device for sterilizing an open-mouthreceptacle with a hot vapor comprises a base having a fluid-container portion adapted to hold an electrically conductive fluid and to provide above the fluid a vapor chamber. The base has a second portion which provides a vapor jet communicating with the above-mentioned chamber and directed exteriorly of the base. The device also includes spaced electrodes in the fluid-container portion for engagement with the fluid, and these electrodes are adapted to be connected to a source of electrical energy for vaporizing the fluid by the passage of electrical current therethrough. The sterilizer is further provided with means for supporting the receptacle with the open mouth thereof in registration with the vapor jet and with the receptacle approximately aligned with the direction of vapor flow from the jet, whereby the vapor tends to flow from the jet centrally of the receptacle to the closed end thereof and then to flow along the walls of the receptacle and out the open mouth thereof. The device further includes a cover co-operatlng with the base to provide an enclosure for confining the receptacle in the vapor. The sterilizing device also includes means for returning vapor condensate to the fluid-container portion for subsequent vaporization by the electrodes. The electrodes cooperate with the walls of the fluid-container portion to form a constricted channel communicating with the return means for controlling the flow of the condensate to the space between the electrodes, thereby to control the rate of vaporization of the fluid.

For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Referring now to the drawing, Fig. 1 is a perspective view of a sterilizing device in accordance with the instant invention with a portion thereof broken away to illustrate details of construction; Figs. 2 and 3 are perspective views, partly in cross section, of the base of a sterilizing device embodying the present invention; and Fig. 4 is an enlarged plan view of a portion of the base illustrating certain details thereof.

Referring now more particularly to Fig. 1 of the drawing, there is illustrated a base l0 formed of an electrically insulating material, for example, a ceramic which may have a glazed or porcelain finish. The base includes a plurality of spaced legs ll. Electrical connection is made through an electrical conductor cord H to concealed electrodes to be described in detail hereinafter. A pair of diametrically disposed handies [3 are provided on the base to facilitate transporting the sterilizer. The base l0 includes on the upper face thereof an annular depression [4 which slopes inwardly toward a circular cover plate l5 preferably made of a suitable insulating material such as glazed ceramic. The plate I5 is attached to the base In by a plurality of screws 22, 22. The circular plate l5 includes a plurality of hollow frusto-conical protuberances l6, l6 each providing a vapor jet and adapted to extend into and support an open-mouth receptacle, for example, a nursing bottle H, in an inverted position. To simplify the illustration, however, only one bottle is shown. Each pro- 3 tuberance [8 has a radial slot 25 which extends through the wall thereof and is directed toward the center of plate IS. The upper surface of plate [5 slopes downwardly from its axis toward its peripheral portion.

A rack i8 is constructed of a plurality of wire loops 28', which are secured to a disc H) on the upper end of a column 2|. Each wire loop 20 is adapted to extend around and support the peripheral body portion of an inverted bottle 11. The column 2 I. is rectangular in cross section, and the lower end thereof is adapted to be removably inserted into a socket 23, also of rectangular cross section, which is axially formed in a frustoconical enlargement 24 on the upper surface of the cover plate l5. The socket 23 so orients the column 2: that each loop 20 is positioned with the central portion of its opening directly over one of the hollow protuberances [6.

A hollow cylindrical cover 26 co-operates with the base 13 to provide anenclosure for confining the bottles I? in the vapor which is generated in aportion of the base to be described hereinafter. The cover 26 hasa closed end 28 and is arranged to fit with its open end resting in the annular depression l4 and with its vertical wall in close engagement with a peripheral flange 30 on the base H]. A knob 3| is attached .to the central portion of the closed end 28of the cover 28 to facilitate handling. The cover 26a1so includes means for restricting the escape of Vapor from the enclosure formed by the base [0 and the cover 26 to control the length of time the vapor is formed, as will be explained subsequently. This means comprises a small aperture or vent 33 in the closed end 28.

Figs. 2 and 3 of thedrawing illustrate in greater detail certain constructional features of the base Id. The latter is provided with a fluid-container portion in the form of a shallow well which is adapted to hold an electrically conductive fluid, for example, ordinary tap water. A pair of spaced electrodes 36, 36, preferably comprising rectangular carbon blocks, are secured to the bottom of the well 35 by means of threaded electrically conductive members 31, 31 which pass'thro-ugh the base 10 and are secured to eX- ternal terminals 38, 38. The latter are connected in a conventional manner to-the electrical conductor cord l2. The spaced electrodes 3 33 are about 30 seconds thus arranged for engagement with any water which may be placed in the well 35 and, by means of the terminals 38, 38 and the cord l2, are adap ed to be connected to a source of electrical energy for vaporizing the water by the passage of electrical current therethrough. A shelf 39 beneath the-cover plate I5 slopes toward the well 35 and, with the cover plate i5 and the upper surface of a small amount of Water in the well 35, forms a vapor chamber 44. Ra- 'dial vapor ducts 43, 43 in the lower surface of the cover plate 15 (see Fig. 3) permit the flow of vapor from the chamber 44 to each vapor jet provided by individual ones of the protuberances it. "Thus the cover plate I5, which comprises a secend portion of the base l3, provides a vapor jet which communicates with the chamber 44 and is directed exteriorly of the base. 1

The base It] also includes a vapor-condensate *well formed by a slight clearance between the periphery of the plate 15 and the shoulder portion of the annular depression I4. At least one, but more preferably three, constricted passages 4| spaced 120 degrees apart on the under side of the cover plate [5, connectthe well 20 to the :flow of steam 4 sloping shelf 39. These passages 4i collect and retard the flow of vapor condensate to the well 35, thereby effectively providing obstructions at the passages 4| to the flow of vapor therethrough in a manner which will be explained in detail subsequently.

Referring now more particularly to Figs. 3 and 4, thewell 35 also includes portions, 41 extending along each of the outer longitudinal sides of the electrodes 36, 38 for controlling the rate of return of the condensate to the space between the electrodes. Each portion 4'l has a sloping side wall wh ch extends from a region near the base of an individual one of the electrodes 36 to the lower edge of the shelf 39. The electrodes 36, 33 in the well 35 are dimensioned with relation to the dimensions of the well 35 so as to provide constricted channels 5%, 50 around the tips of the electrodes for the flow of condensate to the region between the spaced electrodes, thereby to control the rate of vaporization of the water as will be made clear hereinafter. The end portions of the channels ea, 50 preferably have about twice the size of the side portions thereof. Two projections 51 extend a short distance into the space between the electrodes 36, 3B and aid in aligning the electrodes properly during the assembling operation.

Considering now the operation of the sterilizer just described, the unit is placed in operation by removing the cover 26 and inserting a bottle ll through each of the loops 20 of the rack I3 with the open end of each bottle resting on and encompassing an individual one of the hollow protuberances It. Nipples and other paraphernalia to be sterilized may be placed on the cover plate l5 between the protuberances l6 and the column 21. A predetermined quantity of tap water, for example, about two tablespoonfuls, is poured on the cover plate [5. The cover 26 is then immediatel placed in position on the base IE and the cord I2 is connected to a source of electrical energy. The water placed on the cover plate I5 flows into the well 35, covers the spaced electrodes 36, 3S, and causes a relatively heavy initial flow of electrical current between the electrodes. This current flow causes steam to be generated in a short interval of time. In a preferred embodiment of the invention, steam is developed in The steam collects in the vapor chamber 44 and then passes from the vapor chamber through the ducts 43 to the jets formed by the protu- These protuberances support the ister with the vapor .jets and with the bottles approximately aligned with the direction of the from the jets. This causes the from each jet centrally of each bottle to the closed end thereof where it is deflected and caused .to flow along the walls of the bottle and out of the open mouth thereof by way of the radial slot 25. The steam introduced into the bottles I! also displaces the air originally therein through the radial slots 25.

steam to flow Since the steam is concentrated on the interior surface of the bottle wherein the major sterilizing action is required, effective sterilization of the interior of the bottle begins a very short time after the unit is connected to a source'of electrical energy. As the sterilizing operation continues, steam escapes from the radial slots 25 and fllls the enclosure formed .by the base 10 and the cover .26, thus sterilizing .the paraphernalla lying on the top of the cover plate l5 and also sterilizing the exterior of the bottles.

As the sterilization proceeds, the water between the spaced electrodes diminishes in volume due to its being vaporized. However, some of the steam which was generated condenses on the walls of the cover 26 and portions of the base ID. The condensate from the cover 26 and the cover plate I5 flows down to, and is accumulated in, the vapor condensate well 40. This accumulation of water efiectively provides a vapor seal at the constricted passages 4| and thus obstructs the flow of steam therethrough from the vapor chamber 44, so that the generated steam is effectively directed through the hollow protuberances I6 into the bottles i1. After being retarded in the constricted passages 4|, the condensate trickles principally into the portions 41, 41.

As current continues to flow between the spaced electrodes 36, 36, the level of the water therebetween diminishes due to vaporization. The condensate which accumulates in the portions 41, 41, however, tends to have a slightly higher level than the fluid between the spaced electrodes 36, 36 and, therefore, discharges through the constricted channels 50, 50 into the region between the electrodes. These constricted channels afforded by the electrodes 36, 36, cooperating with the walls of the well 35, are effective to control the flow of the condensate from the portions 41, 41 at a desired rate to the space between the electrodes. Since the rate of vaporization is proportional to the magnitude of current flow between the electrodes 36, 36 while the magnitude of this current flow, in turn, depends upon the volume or level of the water between these electrodes, it will be manifest that the constricted channels 56, 50 in combination with the portions 41, 41 are effective to control the rate of vaporization of the water in the well 35. It will also be apparent from the foregoing explanation that the vapor condensate well 40, the constricted passages 4|, 4|, and the shelf 39 constitute a drain for returning vapor condensate to the well 35 for subsequent vaporization by the electrodes 36, 36, thus providing a regenerative action with respect to the vapor. Thus, only a small amount of fluid is required for the vaporization to continue at the proper rate over the required sterilizing interval.

Since the described arrangement has a regenerative action, it is desirable to control the length of time the sterilization continues. This is accomplished by means of the vent 33 in the cover 26. While the major portion of the vapor condenses and is returned to the well 35, a controlled amount escapes from the vent 33 so that the steam from the water, which was initially placed in the well 35, eventually is lost to the exterior of the sterilizing unit thereby automatically terminating the sterilizing interval by interrupting the flow of electrical current between the spaced electrodes 36, 36.

While applicant does not wish the invention to be limited to a particular structural arrangement, the following more important dimensions and values are given by way of example only:

Base

Outer diameter inches 9 Height do 2;;

Cover 26 Height inches 85% Diameter "do-" 81 I Well 35 Length inches 2% Width do 1% Depth (10 Approximate liquid capacity tablespoonfuls 2 Projections 51 Length and widthu inches A Depth do /2 Electrodes 36 Material carbon Length inches 2 Width and height. do

, Channels 50 Width (end portions) inches Width (side portions) do Depth do /2 Portions 47 Length inches' 1 Width at top do /2 Electrode voltage A.C

It will be apparent from the foregoing description that a sterilizing device embodying the present invention has the advantage that it requires but a small amount of electrically conductive fluid during its operation because of the regenerative action afforded by the condensate which is returned to the region between the electrodes. This action also minimizes the amount of electrical energy consumed by the device over the sterilizing interval. The sterilizer of the instant invention also possesses an additional advantage since itquickly generates steam as a result of the relatively large initial current flow which results when the device is connected to a source of electrical energy. Thereafter the current consumption is reduced to a value which is suli'ficient to produce ample vapor for continuing the sterilizing operation. 'A further advantage results from the utilization of the condensate since its controlled discharge into the space between the electrodes is effective to produce suiiicient water therebetween to maintain the proper rate of vaporization. Additionally, the jet structure tends to concentrate the sterilizing steam on the regions of the bottles wherein bacteria are most apt to be prevalent. V

While the operation of the sterilizer of the instant invention and the advantages thereof have been described in connection with narrow-mouth bottles, the same type of operation and advantages apply with respect to wide mouth bottles.

While there have been described what are at present consideredto be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

l. A device for sterilizing an open-mouth re ceptacle with hot vapor comprising, a base having a fluid-container portion adapted to hold an electrlcally conductive fluid and to provide above said fluid a vapor chamber and having a second portion providing a vapor jet communicating with said chamber and directed exteriorly of said base, spaced electrodes in said fluid-container portion for engagement with said fluid and adapted to be connected to a source of electrical energy for vaporizing said fluid by thepassage of electrical current therethrough, an aperturedrack member supported by and in spacedrelationto said base with the aperture thereof. alignedlwith said vapor jet for engaging said receptacle at a circumferentialregion thereof, a hollow protuberance on said second portion and adapted to extend into the open mouth of said receptacle for restraining said receptacle against substantial lateral "movement at the region of the mouth thereof and for co-operating with said rack member to support said receptacle with the open mouth thereof in register with said vapor jet and with said receptacle approximately aligned with the direction of vapor flow from said jet, whereby said vapor tends to flow from said jet centrally of said receptacle to the closed end thereof and then to flow along the walls of said receptacle and out of :the open mouth thereof, and a cover co-operating with said base to provide an enclosure for confining said receptacle in said vapor.

,2. A device for sterilizing an open-mouth receptacle with hot vapor comprising, a base having a fluid-container portion adapted to hold an electrically conductive fluid and to provide above said fluid a vapor chamber and having a second por tion providing a vapor jet communicating with said chamber and directed exteriorly of said base, spaced electrodes in said fluid-container portion for engagement with said fluid and adapted to be connected to a source of electrical energy for vaporizing said fluid by the passage of electrical current therethrough, means for supporting said receptacle with the open mouth thereof in register with said vapor jet and with said receptacle approximately aligned with the direction of vapor flow from said jet, whereby said vapor tends to flow from said jet centrally of said receptacle to the closed end thereof and then to flow along the walls of said receptacle and out of the open mouth thereof, and a cover co-operating with said base to provide an enclosure for confining said receptacle in said vapor and having an aperture therein for controlling the escape of vapor from said enclosure to control the length of time said vapor is formed.

3. A device for sterilizing an open-mouth receptacle with hot vapor comprising, a base having a fluid-container portion adapted to hold an electrically conductive fluid and to provide above said fluid a vapor chamber and having a second portion providing a vapor jet communicating with said chamber and directed exteriorly of said base, spaced electrodes in said fluid-container portion for engagement with said fluid and adapted to be connected to a source of electrical energy for vaporizing said fluid by the passage of electrical current therethrough, means for supporting said receptacle with the open mouththereof in register with said vapor jet and with said receptacle approximately aligned with the direction of vapor flow from said jet, whereby said vapor tends to flow from said jet centrally of said receptacle to the closed end thereof and then to flow along the walls of said receptacle and out of the open mouth thereof, and a cover co-operating with said base to provide an enclosure for confining said receptacle in said vapor, said cover having a vent therein for restricting the escape of vapor from said enclosure to control the length of time said vapor is formed.

4. A device for sterilizing an open-mouth receptacle withhot vapor comprising, a base having a fluid-container portion adapted to holdan electrically conductive fluid and to provide above Of in said fluid'a vapor chamber and having-a second portion providing avapor jet communicating with said chamber and directed exteriorly of said base, spaced electrodes in :said fluid-containerporticn for engagement with said fluid and adapted to be connected to a source of electrical energyfor vaporizing said fluid b the passage of electrical current therethrough, means for supporting said receptacle with the open mouth thereof inregister with said vapor jet and with said receptacle approximately aligned with the direction of vapor flow from said jet, whereby said vapor tends'to flow from said jet centrally of said receptacle to the closed end thereof and then to flow along the walls of said receptacle and out of the open mouth thereof, acover cooperating with said base toprovide an enclosure for confining said receptacle in said vapor, said base includinga vapor condensate well in said enclosure and at least one constricted passage between said well and said fluid-container portion for collecting and retarding t e flow of said condensate to said -fiuid-container portion thereby effectively providing an obstruction at said passage to the flow of said vapor therethrougl'l.

5. A device for sterilizing an open-mouth receptacle with hot vapor comprising, a base having a fluid-container portion adapted to hold an electrically conductive fluid and to provide above said fluid a vapor chamber and having a second portion providing a vapor jet communicating with said =chamber and directed exteriorly of said base, spaced electrodes in said fluid-container portion for engagement with said fluid and adapted to be connected to a source of electrical energy for vaporizing said fluid by the passage of electrical current therethrough, means for supporting said recetpacle with th open mouth thereof in-register with said vapor jet and with said receptacle approximately aligned with the direction of vapor flow from said jet, whereby saidvapor tends to flow from said jet centrally of said receptacle to the closed end thereof and then to flow along the walls of said receptacle and out of the open mouth thereof, and a cover co-operating with said base to providean enclosure for confining said receptacle in said vapor, and means for returning vapor condensate to said fluid-container portion for subsequent vaporization by said electrodes, said electrodes co-operating with the walls'of said fluid-container portion to form a constricted channel communicating with said return means for controlling the flow of said condensate to the spacerbetween said electrodesthereby to control rate of vaporization ofsaid fluid.

6. A device for sterilizing an open-mouth rcceptacle with hot vapor comprising, a basehaving a fluid-container portion adapted tohold an electrically conductive fluid and to provide above-said fluid a Vapor chamber and having a second portion providing a vapor jet communicating with said chamber and directed exteriorly of said base, spaced electrodes in said fiuidcontainer portion for engagement with said fluid andadaptedto be connected to a source of electrical energy for vaporizing said fluid by the passage of electrical current therethrough, means for supporting said receptacle with the open mouth thereof in register with said vapor jet and with said receptacle approximately aligned with the direction of vapor flow from said jet, whereby said vapor tends to flow from said jet centrally of said receptacle to the closed end thereof and then to flow along the walls of said receptacle and out of the open mouth thereof, a cover co-operating with said base to provide an enclosure for confining said receptacle in said vapor, and means for returning vapor condensate to said fluid-container portion for subsequent vaporization by said electrodes, said electrodes in said fluid-container portion being dimensioned with relation to the dimensions of said fluid-container portion to provide a constricted channel for the flow of said condensate to the region between said spaced electrodes to control the rate of vaporization of said fluid.

'I. A device for sterilizing an open-mouth receptacle with hot vapor comprising, a base having a fluid-container portion adapted to hold an electrically conductive fluid and to provide above said fluid a vapor chamber and having a second portion providing a vapor jet communicating with said chamber and directed exteriorly of said base,

spaced electrodes in said fluid-container portion for engagement with said fluid and adapted to be connected to a source of electrical energy for vaporizing said fluid by the passage of electrical current therethrough, means for supporting said receptacle with the open'mouth thereof in register with said vapor jet and with said receptacle approximately aligned with the direction of vapor flow from said jet, whereby said vapor tends to flow from said jet centrally of said receptacle to the closed end thereof and then to flow along the walls of said receptacle and out of the open mouth thereof, a cover co-operating with said base to provide an enclosure for confining said receptacle in said vapor, and means for returning vapor condensate to said fluid-container portion for subsequent vaporization by said electrodes, said electrodes co-operating with the walls of said fluid-container portion to form a constricted channel communicating with said return means for controlling the flow of said condensate to the space between said electrodes thereby to control the rate of vaporization of said fluid, said cover having an aperture therein for controlling the escape of vapor from said en- 10 closure to control the length of time said vapor is formed.

8. A device for sterilizing an open-mouth receptacle with hot vapor comprising, a base having a fluid-container portion adapted to hold an electrically conductive fluid and to provide above said fluid a vapor chamber and having a second portion providing a vapor jet communicating with said chamber and directed exteriorly of said base, spaced electrodes in said fluid-container portion for engagement with said fluid and adapted to be connected to a source of electrical energy for vaporizing said fluid by the passage of electrical current therethrough, means for supporting said receptacle with the open mouth thereof in register with said vapor jet and with said receptacle approximately aligned with the direction of vapor flow from said jet, whereby said vapor tends to flow from said jet centrally of said receptacle to the closed end thereof and then to flow along the walls of said receptacle and out of the open mouth thereof, a cover co-operating with said base to provide an enclosure for confining said receptacle in said vapor, and a drain for returning vapor condensate to said fluid-container portion for subsequent vaporization by said electrodes, said base providing a vapor condensate well in said enclosure and at least one constricted passage between said well and said Vapor chamber for collecting and retarding the flow of said condensate to said fluid-container portion thereby effectively providing an obstruction at said passage to the flow of said vapor therethrough.

OLIVER H. BREWSTER.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,610,186 Verville Dec. '7, 1926 2,158,692 Duberstein et al. May 16, 1939 

